let max a b =
   if a > b then a else b
   ;;

let func a b =
   if a > b then a + b else a - b
   ;;

let func2 a b c d =
   if a > b then a  +. b else c + d
   ;;

let x = 1;;

let func3 a b =
   if a > b then x + 1 else x - 1;;

//x is function's argument;;
let func4 x =
   if x > 1 then x else 1;;

//Error!! Undefined y;;
let func5 a b =
   if a > b then x + y else x - y;;

//Error!! x is Int;;
let func6 a b =
   if a > b then x +. 1.0 else 2.9;;

//Error!! b is not argument and Undefined variable;;
let func7 a =
   if a > b then a else b;;

//execute;;
max 3 2;;
func 1 2;;
func 2 1;;

//Error!! argument must Int;;
func -1.0 -2.0;;
